Newborn mouse

In the newborn mouse system (Table II), the (+) anti dihydrodiol epoxide is clearly more effective than benzo[ajpyrene but this is not the case in initiation-promotion studies or in complete carcinogenesis studies on mouse skin. Nevertheless, there is always... 

The role of N-sulfonyloxy arylamines as ultimate carcinogens appears to be limited. For N-hydroxy-2-naphthylamine, conversion by rat hepatic sulfotransferase to a N-sulfonyloxy metabolite results primarily in decomposition to 2-amino-l-naphthol and 1-sulfonyloxy-2-naphthylamine which are also major urinary metabolites and reaction with added nucleophiles is very low, which suggests an overall detoxification process (9,17). However, for 4-aminoazobenzene and N-hydroxy-AAF, which are potent hepatocarcinogens in the newborn mouse, evidence has been presented that strongly implicates their N-sulfonyloxy arylamine esters as ultimate hepatocarcinogens in this species (10,104). This includes the inhibition of arylamine-DNA adduct formation and tumorigenesis by the sulfotransferase inhibitor pentachlorophenol, the reduced tumor incidence in brachymorphic mice that are deficient in PAPS biosynthesis (10,115), and the relatively low O-acetyltransferase activity of mouse liver for N-hydroxy-4-aminoazobenzene and N-OH-AF (7,114,115). 

Busby WF Jr, Cfoldman ME, Newbeme PM, Wogan GN Tumorigenicity of fluoranthene in a newborn mouse lung adenoma bioassay. Carcinogenesis 5 1311-1316, 1984... 

The biochemical parameters of myelination appear to be controlled in a coordinated manner. That is, the parameters we measured responded in the same direction and degree to a certain condition of growth. For example, the cyclic nucleotide phospho-hydrolase and incorporation of into lipids both were less active in cultures from the newborn mouse than from the 15 day fetus. In addition the developmental pattern of all of the activities measured occurred in parallel and were all highest at about the same growth period. This coordinated control suggests that they are derived from a central source, such as a single cell type (for example, oligodendroglia) of brain. 

Fujii K (1991) Evaluation of the newborn mouse model for chemical tumorigenesis. Carcinogenesis 12 1409-1415... 

There is no evidence that inositol is a dietary essential, because it is synthesized by aU eukaryotic cells. Infants may have a higher requirement than can be met by endogenous synthesis, and dietary inositol is a growth factor for the newborn mouse. In female gerbils, inositol is a dietary essential, and deficiency... 

Recent studies have shown that EGCG has a neuroprotective effect against hippocampal neuronal damage following global ischemia in the gerbils. Tea catechins protected the cultured newborn-mouse cerebral nerve cells from death induced... 

Qinli et al. [562] studied the preventive effect of necrostatin-1 (Nec-1) on neural cell death induced by aluminum (Al). Al-exposed primary cultures of newborn mouse cortical cells were separately treated with 3-methylamphetamine (3-MA), benzyloxycarbonylvalyl-alanyl-aspartic acid (O-methyl)-fluoro-methylketone (zVAD-fmk), and Nec-1. The cell viabilities inhibited by Al were enhanced by 3-MA, zVAD-fmk, and Nec-1. Administration of Nec-1 on AT treated mice significantly improved learning and memory retention in the Morris water maze task, decreased the neural cell death, and inhibited the expression of AD-related proteins in the mouse brain. 

On the catabolic side of RNA and DNA metabolism aside from the nucleases which have already been discussed, Zaruba et al. (Z2) have reported on the presence of phosphodiesterases specific for 3 and 5 linkages in skin of newborn mouse. Phosphodiesterases of at least three types present in epidermis have also been mentioned by de Bersaques (B17). Zaruba et al. (Z3) reported that phosphodiesterase activity was higher in psoriasis lesions than in normal epidermis or in adjacent uninvolved skin of psoriasis. 

Z2. Zaruba, F., Karasek, M. A., and Farber, E. M., Isolation and properties of a phosphodiesterase from newborn mouse skin. J. Invest. Dermatol. 49, 537 (1967). 

Busby WF Jr, Stevens EK, Martin CN, et al. 1989. Compartive lung tumorigenicity of parent and mononitro-polynuclear aromatic hydrocarbons in the BLU Ha newborn mouse assay. Toxicol Appl Pharmacol 99(3) 555-563. 

Wislocki PG, Bagan ES, Lu AY, et al. 1986. Tumorigenicity of nitrated derivatives of pyrene, benz[a]anthracene, chrysene and benzo[a]pyrene in the newborn mouse assay. Carcinogenesis 7 1317-1322. 

Lewtas J, Dooley K, Von Tungeln L, et al. 1993. Comparative tumorgenicity of complex environmental mixtures in the newborn mouse and mouse skim tumor assays. Proc Am Assoc Cancer Res 34 117. 

Maternal Immunoglobulins (antibodies) contained in ingested breast milk are transported across the intestinal epithelial cells of the newborn mouse and human by transcytosis (Figure 17-34). The F receptor that mediates this movement binds antibodies at the acidic pH of 6 found in the intestinal lumen but not at the neutral pH of the extracellular fluid on the basal side of the Intestinal epithelium. This difference in the pH of the extracellular media on the two sides of intes-... 

In the present study the newborn mouse was able to survive 40 minutes under the experimental conditions of anoxia employed. 

Sudo, H., Kodama, H., Amagai, Y., Yamamoto, S., and Kasai, S., 1983, In vitro differentiation and calcification in a new clonal osteogenic cell line derived from newborn mouse calvaria, J. Cell Biol 96 191-198. 

Several other experiments on cultured epidermal cells deserve mention. Newborn mouse epidermal cells cultured in semm-free defined medium respond to retinoid treatment in a dose-dependent manner, with an increase in both DNA and RNA synthesis (Spom et al., 1973). The response is extremely sensitive with an EDjq of 4 X 10 Af for all-rrmw-retinoic acid (Spom et al., 1976) and has been standardized in a sensitive assay for measurement of stmcture-function... 

Endosialidase is also of interest as therapeutic agent. For instance, it has been described as an efficient agent in the treatment of septicemia and meiungitis in E. coli K1 infected rats [195]. Small quantities of recombinant endoNE injected intraperitoneally into newborn mouse pups to remove polysialic acid from the bacterial surface are able to prevent the development of bacteremia and death in an experimental... 

Fig. 10. Capillary from the brain of a newborn mouse injected subcutaneously with a single toxic dose of cadmium and killed after 8 h. There is an accumulation of platelets in the vessel. One platelet is plugging a gap in the endothelial wall (arrow). Note also the accumulation of lipid droplets (Id), thinning of the capillary wall, and intracellular vacuoles (v). Reproduced by permission of W.S. Webster and AA. Vcdois, J. Neuropathol. E cp, Neurol. 40, 247-257, 1981.

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